Wissam Tawil was a commander of Hezbollah's elite Radwan forces and the most senior Hezbollah officer killed so far in the conflict, a senior source in Lebanon said, adding he played a leading role in directing its operations in the south.

More than 130 Hezbollah fighters including Radwan members have been killed in hostilities since the group's Palestinian ally Hamas attacked Israel from Gaza on Oct. 7, igniting a conflict that has rippled around the region.

It has marked the deadliest confrontation between Israel and the Iran-backed Hezbollah since they went to war in 2006, with Hezbollah firing guided rockets and other weapons at Israeli positions and Israel launching air and artillery strikes.

Tens of thousands of people on both sides of the frontier have fled, and the fighting has raised concern of an even wider conflict.

Tawil and another Hezbollah fighter were killed when the car they were in was struck in the village of Majdal Selm, some 6 km (3.7 miles) from the border, three sources in Lebanon said.

There was no immediate comment from Israel.

Hezbollah circulated photographs of Tawil with leaders of the heavily armed, Shi'ite Muslim group including Secretary General Sayyed Hassan Nasrallah and Imad Mughniyeh, its military commander who was killed in Syria in 2008.

Another photo showed him sitting next to the late leader of the Iranian Revolutionary Guards' Quds Force, Qassem Soleimani, who was killed by a U.S. drone strike in Baghdad four years ago.

The senior source said Tawil's death marked a big blow given his experience including deployments with Hezbollah in Syria and Iraq.

Hezbollah says its current campaign against Israel aims to support Palestinians in the Gaza Strip, which has been devastated by an Israeli offensive since Hamas' Oct. 7 attack. The hostilities between Hezbollah and Israel have largely been contained to areas near the Lebanese-Israeli border.

Tensions spiked higher last week when an Israeli strike killed deputy Hamas leader Saleh al-Arouri in Beirut's southern suburbs, an area controlled by Hezbollah. Israel has neither confirmed nor denied its responsibility for that attack.

Hezbollah said on Saturday it had hit a key Israeli observation post with 62 rockets as a "preliminary response" to Arouri's killing.

Other members of the Radwan force killed during the hostilities include Abbas Raad, son of a leading Hezbollah politician. He was killed in an Israeli strike in November.

Hezbollah's secretary-general Sayyed Hassan Nasrallah warned Israel in two televised addresses last week not to launch a full-scale war on Lebanon. "Whoever thinks of war with us - in one word, he will regret it," Nasrallah said.

On Sunday, Hezbollah deputy leader Naim Qassem said the group did not want to "initiate total war, but if Israel decides to wage total war on us then we in the field will respond with total war without hesitation and with all we have".

Nineteen Hezbollah fighters have been killed in Syria since the hostilities erupted.

The Hamas-Israel war has drawn in Iran-aligned groups across the region, with the Houthis of Yemen firing on ships in the Red Sea and launching missiles and drones at Israel, and Tehran-backed militias in Iraq attacking U.S. forces in Iraq and Syria.